Processes and systems for catalytic manufacture of wax ester derivatives

ABSTRACT

Processes for transesterifying wax esters. Implementations may include: providing a feedstock including wax esters, contacting the feedstock with a lipase, and catalytically transesterifying the wax esters in the feedstock with the lipase to form a transesterified product. An oxidative stability index (OSI) of the transesterified product may be greater than an OSI of the feedstock.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/456,166, filed Nov. 23, 2021, which is a continuation of U.S. Pat.Application No. 14/578,075, filed Dec. 19, 2014, now U.S. Pat. No.11,248,245, issued Feb. 15, 2022, each of which is incorporated byreference herein in its entirety.

SEQUENCE LISTING

This document contains the material in and hereby incorporates entirelyherein by reference the sequence listing file in XML format filedherewith named FloraTech110.xm1, created Jan. 24, 2023, which is 3409bytes in size.

BACKGROUND 1. Technical Field

Aspects of this document relate generally to systems and processes forreacting and processing wax esters and wax ester derivatives.

2. Background Art

A wax ester is formed from the chemical reaction of a fatty acid and afatty alcohol, which results in the formation of an ester group thatlinks two carbon chains. Wax esters are found in various animals andplants, including the jojoba plant (Simmondsia chinensis). Wax estersare used in various applications, including in cosmetic and personalcare products.

SUMMARY

Implementations of processes for transesterifying wax esters mayinclude: providing a feedstock including wax esters, contacting thefeedstock with a lipase, and catalytically transesterifying the waxesters in the feedstock with the lipase to form a transesterifiedproduct. An oxidative stability index (OSI) of the transesterifiedproduct may be greater than an OSI of the feedstock.

Implementations of process for transesterifying wax esters may includeone, all, or any of the following:

The transesterified product may include no methyl esters.

The feedstock may further include an antioxidant and catalyticallytransesterifying the wax esters in the feedstock with the lipase mayfurther include catalytically transesterifying without one of removingand degrading the antioxidant in the feedstock.

The feedstock may further include a skin conditioning agent and avolatile compound and catalytically transesterifying the wax esters inthe feedstock with the lipase may further include catalyticallytransesterifying without removing or degrading the skin conditioningagent and the volatile compound in the feedstock.

The wax esters of the feedstock may be jojoba wax esters.

The jojoba wax esters may further include hydrogenated jojoba waxesters.

A dropping point of the transesterified product may be greater than adropping point of the feedstock and the dropping point may increase as apercentage of hydrogenated jojoba wax esters in the feedstock increases.

Implementations of a process for transesterifying wax esters may includeproviding a feedstock including wax esters, contacting the feedstockwith a lipase, and catalytically transesterifying the wax esters in thefeedstock with the lipase to form a transesterified product. Thecatalytic transformation may take place at greater than or equal to 98%yield.

Implementations of processes for transesterifying wax esters may includeone, all or any of the following:

The transesterified product may include no methyl esters.

The feedstock may further include an antioxidant and catalyticallytransesterifying the wax esters in the feedstock with the lipase mayfurther include catalytically transesterifying without removing ordegrading the antioxidant in the feedstock.

The wax esters of the feedstock may be jojoba wax esters.

The jojoba wax esters may further include hydrogenated jojoba waxesters.

A dropping point of the transesterified product may be greater than adropping point of the feedstock and the dropping point may increase as apercentage of hydrogenated jojoba wax esters in the feedstock increases.

Implementations of a process for transesterifying wax esters may includeproviding a feedstock including jojoba wax esters, contacting thefeedstock with a lipase catalyst, and catalytically transesterifying thejojoba wax esters in the feedstock with the lipase to form atransesterified product. The yield of the catalytic transesterificationmay be greater than 4001 kilograms of product per kilogram ofimmobilized lipase catalyst.

Implementations of a process of transesterifying wax esters may includeone, all, or any of the following:

The transesterified product may include no methyl esters.

The feedstock may further include an antioxidant and catalyticallytransesterifying the jojoba wax esters in the feedstock with the lipasemay further include catalytically transesterifying without removing ordegrading the antioxidant in the feedstock.

The feedstock may further include a skin conditioning agent and avolatile compound and catalytically transesterifying the jojoba waxesters in the feedstock with the lipase may further includecatalytically transesterifying without removing or degrading the skinconditioning agent the skin conditioning agent and/or the volatilecompound in the feedstock.

The jojoba wax esters may further include hydrogenated jojoba waxesters.

A dropping point of the transesterified product may be greater than adropping point of the feedstock and the dropping point of thetransesterified product may increase as a percentage of hydrogenatedjojoba wax esters in the feedstock increases.

The catalytic transesterification may take place at a greater than orequal to 98% yield.

The foregoing and other aspects, features, and advantages will beapparent to those artisans of ordinary skill in the art from theDESCRIPTION and DRAWINGS, and from the CLAIMS.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations will hereinafter be described in conjunction with theappended drawings, where like designations denote like elements, and:

FIG. 1 is a flow chart of a conventional chemically catalyzedtransesterification process;

FIG. 2 is a flow chart of an enzymatically catalyzed transesterificationprocess;

FIG. 3 is a process diagram showing an implementation of threeenzymatically catalyzed transesterification reactors in series;

FIG. 4 is a comparison chart showing the distribution of jojoba waxester carbon lengths in a transesterified product stream from a jojobawax ester feedstock for a chemically catalyzed process and an enzymecatalyzed process;

FIG. 5 is a comparison chart showing the distribution of jojoba waxester carbon lengths in a transesterified product stream from a jojobawax ester combined with about 20% by weight of hydrogenated jojoba waxester feedstock for a chemically catalyzed process and an enzymecatalyzed process;

FIG. 6 is a comparison chart showing the distribution of jojoba waxester carbon lengths in a transesterified product stream from a jojobawax ester combined with about 30% by weight of hydrogenated jojoba waxester feedstock for a chemically catalyzed process and an enzymecatalyzed process;

FIG. 7 is a comparison chart showing the distribution of jojoba waxester carbon lengths in a transesterified product stream from a jojobawax ester combined with about 50% by weight of hydrogenated jojoba waxester feedstock for a chemically catalyzed process and an enzymecatalyzed process.

DESCRIPTION

This disclosure, its aspects and implementations, are not limited to thespecific components, assembly procedures or method elements disclosedherein. Many additional components, assembly procedures and/or methodelements known in the art consistent with the intended processes andsystems for transesterifying wax esters will become apparent for usewith particular implementations from this disclosure. Accordingly, forexample, although particular implementations are disclosed, suchimplementations and implementing components may comprise any shape,size, style, type, model, version, measurement, concentration, material,quantity, method element, step, and/or the like as is known in the artfor such processes and systems for transesterifying wax esters, andother implementing components and methods, consistent with the intendedoperation and methods.

Transesterification involves the process of exchanging acyl groupslocated on each side of a ester group with an acyl group contained in analcohol group, as illustrated below:

Transesterification for naturally occurring or structured or syntheticesters permits altering of various physical properties of thetransesterified product when compared to the original feedstock. Bynon-limiting example, physical properties such as viscosity, droppingpoint, oil (oxidative) stability index (OSI), carbon chain distribution,and other properties of the transesterified product may be greater,equal to, or less than the corresponding values of the original waxester-containing feedstocks. These changes take place at least in partbecause the chain lengths of the resulting ester products are randomizedcompared to the distribution in the original wax ester feedstock, whichmay alter the functionality of the transesterified material in a mixtureand/or the thermal properties of the material.

Conventionally, transesterification of wax esters is accomplished usingseveral different methods. Methods and systems for transesterifyingjojoba oil that include the use of an acidic bentonite-type clay attemperatures between 150° C. - 350° C. are disclosed in U.S. Pat. No.4,329,298 to Brown, et al., entitled “Isomerization of Jojoba Oil andProducts Thereof,” filed Aug. 15, 1980 and issued May 11, 1982 and inU.S. Pat. No. 4,360,387 to Brown, et al., entitled “Isomorphous JojobaOil Compositions Containing Trans-Isomerized Jojoba Oil,” filed Mar. 9,1981, issued Nov. 23, 1982, the disclosures of both of which are herebyincorporated entirely herein by reference. When using the processdescribed in the foregoing patents for transesterification, a 5%-10%loss of the original jojoba oil was observed.

Other conventional transesterification reactions use a chemicalcatalyst, such as sodium methylate (methoxide) or sodium hydroxide.While the reaction is catalytic, side reactions between the catalyst andcomponents of the feedstock and/or reactants occur duringtransesterification process. These side reactions create byproducts thatreduce the yield of the process and alter the properties of thetransesterified product. Some of the property changes occur because ofdamage/changes to the feedstock esters caused by the high temperatures(100° C. - 230° C.) and low pressures (< 7 mmHg) required to carry outchemical catalytic transesterification. Other property changes occurbecause these conditions and/or the chemical catalysts themselvesdegrade, destroy, or reduce the effectiveness of other subcomponents ofthe wax ester feedstock. Where the wax ester feedstock is derived from anatural source, such as in a jojoba wax ester feedstock, existingantioxidants, sterols, hydrocarbons, and other volatile compounds(volatile in comparison to the volatility of the wax esters) react withthe chemical catalyst in side reactions. The resulting transesterifiedproduct may have little or none of any of these components remainingintact following chemical catalytic transesterification and/or mayreduce the effectiveness of these components. Furthermore, thetransesterified product may include artifacts of these components whichare undesirable or have undesirable effects in the product or subsequentmixtures that include the product.

Chemically catalyzed transesterification of wax esters is carried out ina batch reactor, and the catalyst cannot, accordingly, be recovered forreuse from the transesterification product. Referring to FIG. 1 , aprocess flow diagram for a conventional transesterification process isillustrated. As illustrated, the feedstock containing wax esters isprocessed in a batch catalytic reaction. Following batch processing, thereaction is stopped using an acid and/or water such as citric acid toneutralize the remaining catalyst. At this point, the reactor contentsare then checked for the presence of free fatty acids, which, if presentrequires the use of a neutralization process for the free fatty acids.The batch reactants are then moved into a waste separation step, inwhich the solution is washed with soft water to remove soaps and saltsin the reactor material and separate them from the oil/lipid portion ofthe reactor material that contains the transesterified product to form awaste stream and a transesterified product stream. The transesterifiedproduct in the transesterified product stream is then bleached to removeremaining color bodies, soaps, and other undesirable byproducts formedduring the chemically catalyzed transesterification reaction. Thetransesterified product stream is then deodorized and votated to producea finished transesterified product. The process of votation is acontrolled crystallization process or tempering process in which thetransesterified product is agitated under controlled conditions to forma transesterified product with a desired consistency and crystallinestructure for later use. Votation includes various heating, chilling,flash chilling, and other pressure adjustments to provide the desiredconsistency and/or structure.

In this document, various processes for transesterifying wax esters aredisclosed that use enzymes to catalytically facilitate thetransesterification reaction. In particular implementations, the enzymesare lipases, which are proteins that various biological organisms use tocatalyze the hydrolysis and/or esterification of various compounds, suchas lipids. As used herein, “lipase” means any enzyme or protein capableof being used in a transesterification reaction of a wax ester.

Referring to FIG. 2 , a process flow diagram for an enzymaticallycatalyzed transesterification process is illustrated. As illustrated,the wax ester feedstock passes through one or more catalytic reactorsthat allow a continuous catalytic transesterification reaction to takeplace. While it is possible to batch process wax ester feedstocks usingenzymes, continuous processing has many well-known advantages over batchprocessing. Following the continuous catalytic transesterificationreaction, the transesterified product is deodorized and votated toproduce a finished transesterified product stream. As can be observed,there are fewer process steps in an enzymatically catalyzedtransesterification process. Furthermore, as will be discussed in detailbelow, because there are little or no side reactions between the enzymecatalysts and the reactants, while the transesterification results ofthe enzyme catalyzed process are very similar to chemically catalyzedprocess, the properties and components of an enzyme catalyzedtransesterified product stream differ in important ways while retainingessentially the same functional characteristics.

Referring to FIG. 3 , a process flow diagram of an implementation of acontinuous enzymatic reactor system 2 for enzymatic catalyzedtransesterification of wax esters is illustrated. As illustrated, thesystem 2 includes three reactors 4, 6, 8 connected in series. Eachreactor contains the enzyme and is designed to place the incoming waxester feedstock 10 in contact with the enzyme. Following processing, thetransesterified product 12 exits the final reactor 8 for subsequentprocessing/collection. In particular implementations, the enzyme isimmobilized on a substrate material designed to facilitate interactionof the incoming wax ester feedstock. In other implementations, theenzyme is immobilized on the internal structure(s) of the reactor itselfor is free flowing within the reactor system and recycled back to thereactor(s). In the implementation illustrated in FIG. 3 , the reactorsare packed bed reactors. Those of ordinary skill in the art will readilybe able to select various reactor components and other piping, pumps,filters, and other process equipment to facilitate the use of theenzymatic reactors using the principles disclosed herein.

Many different enzymes may be employed in enzymatic catalytictransesterification reactions for wax esters, including those that arederived/obtained from biological organisms, those made synthetically,and those that are entirely artificial, whether made biologically and/orsynthetically. For those enzymes that are lipases, these may include,one, some, any, or any combination of lipases derived from the followingorganisms: Aspergillus niger, Aspergillus oryzae, Bacillus subtilis,Bacillus thermocatenulatus, Burkholderia cepacia, Burkholderia glumae,Candida rugosa, Candida antarctica A, Candida antarctica B, Candidacylindracea, Candida parapsilosis, Chromobacterium viscosum, Geotrichumcandidum, Geotrichum sp., Mucor miehei, Humicola lanuginose, Penicilliumcamembertii, Penicillium chrysogenum, Penicillium roquefortii,Pseudomonas cepacia, Pseudomonas aeruginosa, Pseudomonas fluorenscens,Pseudomonas fragi, Pseudomonas alcaligenes, Pseudomonas mendocina,Rhizopus arrhizus, Rhizomucor miehe, Staphylococcus hyicus,Staphylococcus aereus, Staphylococcus epidermidis, Staphylococcuswarneria, Staphylococcus xylosus, Thermomyces lanuginosus, Aspergillussp., Bacillus sp., Burkholderia sp., Candida sp., Chromobacterium sp.,Geotrichum sp, Mucor sp, Humicola sp, Penicillium sp, Pseudomonas sp,Rhizopus sp., Staphylococcus sp, and Thermomyces sp.

In particular implementations, the lipase may be the following: a lipasefrom Thermomyces lanuginosus marketed under the tradenames LIPOZYME TLIM™ or LIPEX™ by Novozymes A/S of Bagsvaerd, Denmark and immobilized ona substrate also manufactured by Novozymes. A representative sequencelisting of the lipase is included as SEQ ID NO: 1 herein. In otherimplementations, the lipase may be that marketed under the tradenameNOVOZYM™ by Novozymes, A/S derived from Candida antarctica, arepresentative sequence listing for which is included as SEQ ID NO: 2herein. In various implementations, the lipases may be any of thefollowing: those marketed under the tradenames CALB L™, NOVOZYME 435™,NOVOCOR AD L™, and LIPOLASE 100L™ by Novozymes; those marketed under thetradenames CALB™, CALA™, and CRL™ by c-LEcta, GMBH of Leipzig, Germany;those marketed under the tradenames LIPASE A “AMANO” 12™, LIPASE AY“AMANO″™ 30SD™, LIPASE G “AMANO” 50™, LIPASE R “AMANO″™, LIPASE DF“AMANO” 15™, LIPASE MER “AMANO”™, and NEWLASE F™ by Amano Enzyme Inc. ofNagoya, Japan; those marketed under the tradenames LIPASE MY™, LIPASEOF™, LIPASE PL™, LIPASE PLC/PLG™, LIPASE QLM™, LIPASE QLC/QLG™, LIPASESL™, and LIPASE TL™ by Meito Sangyo Co., Ltd., of Nagoya, Japan.

In other implementations, the lipase may be a lipase from Candidaantarctica A, a lipase from Candida antarctica B, Candida rugosa or anycombination thereof. In various implementations, the lipases may be anydisclosed in U.S. Pat. Application Publication No. 20140017741 (the ‘714publication) to Nielsen, et al., entitled “Esterification Process,”filed Oct. 1, 2013 and published Jan. 16, 2014, the disclosure of whichis hereby entirely incorporated herein by reference. Those lipasesdisclosed in the sequence listings for the various patent applicationslisted in para. [0026] - [0029] in the ‘741 publication, previouslyincorporated by reference, each of which applications are herebyentirely incorporated by reference herein, may also be those utilized inparticular implementations. In various implementations, the lipases maybe those have at least 60%, at least 70%, at least 80%, at least 90%, atleast 95%, at least 96%, at least 97%, at least 98%, or even at least99% identity to any of the lipases disclosed herein, in the ‘714publication, and in the patent applications disclosed in the ‘714publication, all of which have been previously incorporated byreference.

A wide variety of wax esters may be processed using the enzymaticcatalytic transesterification processes disclosed herein. Bynon-limiting example, wax esters contained in the following materialsmay be included in the wax ester feedstocks processed using theprinciples disclosed herein: beeswax, Chinese wax, shellac wax, whalespermaceti, lanolin, carnauba wax, ouricuri wax, jojoba oil, candelillawax, esparto wax, Japan wax, rice bran oil, sunflower wax, ozocerite,ozokerite, and montan wax. Any other natural or synthetically producedwax esters may also be processed using the principles disclosed herein.Various examples are discussed in this document regarding wax esters injojoba oil feedstocks, but these examples are merely given to illustratethe principles disclosed herein.

Jojoba oil derived from the seeds of the jojoba plant contains waxesters and other components that have been noted to be useful forvarious functions. These include steryl esters, sterols, and varioushydrocarbons that can be useful as skin conditioning agents in cosmeticsand personal care products. Antioxidants, like tocopherols, are alsoincluded, along with various volatile ingredients naturally present inthe oil, which are volatile in comparison with the wax esters. The waxesters in jojoba oil generally vary between 34 and 48 carbons in length.A detailed analysis of the wax ester distribution, structuralcharacteristics, and other components in jojoba oil may be found in thepaper by Thomas K. Miwa, entitled “Structural Determination and Uses ofJojoba Oil,” J. Amer. Oil Chem. Soc., Vol. 61, No. 2 (February 1984), p.407-410, the disclosure of which is hereby incorporated entirely hereinby reference. It has been observed that jojoba oil derived from plantsfrom South America, Israel, and North America differ somewhat inchemical composition, but these differences are slight and have not beenobserved to produce any effect on the product functionalcharacteristics. Details on the composition of jojoba oil from Chile maybe found in the article by Cappillino et al., entitled “Composition ofChilean Jojoba Seeds,” Ind. Crops and Prod., v. 17, p. 177-182 (2003),the disclosure of which is hereby incorporated entirely herein byreference. Additional information on the differences in jojoba oilproduced from jojoba seeds from Chile, North America, Israel, and therest of South America may be found in the presentation by Cappillino etal., “Composition of Chilean Jojoba Seed,” given at the 5th New CropsSymposium in Atlanta, GA Nov 10-13, 2001, a copy of which is includedherewith at Appendix B, the disclosure of which is hereby incorporatedentirely herein by reference.

Transesterification of jojoba oil has conventionally been done using thechemically catalyzed processes discussed herein. When such chemicalcatalyzed processes are used, side reactions form various fatty acidmethyl esters and leave various free fatty alcohols when sodiummethoxide is used. The resulting transesterified product stream mayinclude 5% or less by weight of these fatty acid methyl esters, whichmay function as an emollient, and the free fatty alcohols, which mayfunction as an emollient and viscosity controller. As was previouslydiscussed however, the reaction of the chemical catalyst removes ordegrades the steryl esters, sterols, tocopherols, hydrocarbons, andvolatile ingredients in the jojoba oil. This degradation and/or removalof these components changes the functionality and physical properties ofthe transesterified product stream. In particular, the degradationand/or removal of the tocopherols and other naturally occurringantioxidants reduces the OSI of the transesterified product to below theOSI of the original jojoba oil. As jojoba oil includes between about 0to about 500 ppm of tocopherols with the major component beinggamma-tocopherol, elimination of the natural tocopherols has asignificant effect on the oxidative stability of the mixture. Anaddition of 500 ppm of tocopherols can enhance the oxidative stabilityof the material by about 50% to about 200% of the original oxidativestability.

Table 1 lists some process parameters and some characteristics of thetransesterified product stream for a chemically catalyzedtransesterification process and those for an enzymatically catalyzedtransesterification process.

TABLE 1 Process Parameter Chemical Catalyst Enzymatic Catalyst ReactionTemperature 100° C. - 230° C. 10° C. - 70° C. Reaction Pressure < 7 mmHg 760 mm Hg (ambient) Product Color Increased (changes color) Nochanges Soap Formation Yes No change Transesterification Yield 85% - 95%>98%

Table 2 shows observed effect of the chemically catalyzed process andvarious enzymatically catalyzed processes on the various naturallypresent components in jojoba oil as well as side reaction byproducts.

TABLE 2 Transesterified Product Component Skin Care Formula FunctionChemical Catalyst Enzyme Catalyst Steryl Esters Skin Conditioning AgentRemoved/Degraded Functionally Unaffected Sterols Skin Conditioning AgentRemoved/Degraded Functionally Unaffected Tocopherols AntioxidantRemoved/Degraded Functionally Unaffected Hydrocarbons Skin ConditioningAgent Removed/Degraded Unchanged Fatty Acid Methyl Esters EmollientFormed, <5% Not formed Free Fatty Alcohols Emollient, ViscosityController Formed, <5% Not formed Volatile Ingredients SensoryAttributes Removed/Degraded Functionally Unaffected

As can be observed from the table, the enzymatic transesterificationprocess takes place at the melting point of the jojoba oil (and anyhydrogenated jojoba oil included in the feedstock) under substantiallyatmospheric pressure. The reaction also proceeds withoutremoving/degrading the tocopherols or volatiles naturally contained inthe jojoba oil. Also, the enzyme catalyzed process does not createmethyl esters or free fatty alcohols which may limit the applications ofthe transesterified product as they affect the emollient and/orviscosity behavior of the product. Furthermore, the degradation/removalof the tocopherols in the chemically catalyzed process adversely affectsthe oxidative stability (measured by the OSI) and accordingly, the shelflife, of the transesterified product. The addition of fatty acid methylesters creates different material spreading and refractive properties inthe chemically transesterified product, even at levels up to about 5% byweight.

Several examples of chemically catalyzed transesterification reactionscompared with enzymatically catalyzed transesterification reactions aredisclosed in this document, including in FIGS. 4-7 . These will beconsidered in turn.

Example 1. Chemical Catalytic Batch Process vs. Enzymatically CatalyzedBatch Process

A 1 liter 3-necked glass flask equipped with an agitating blade wasloaded with 800 g of refined jojoba oil. The oil was heated to 110 C anddried under vacuum for 30 minutes. After drying was completed, a smallamount of sodium methylate (0.3% by weight) was added to the mixture.The transesterification reaction was agitated under vacuum at 120° C.for two hours. The catalyst was then neutralized with 1 g of citric acidand then treated with a silica and bleaching clay mixture to removecolor induced by the reaction and other residual impurities. Thetransesterified product was a yellow liquid.

A 2 liter jacketed glass reactor equipped with an agitating blade wasloaded with 1.2 kg of refined jojoba oil and 48 g (4% by weight) ofLIPOZYME TL IM™ (Thermomyces lanuginosus lipase) from Novozymes. A layerof nitrogen was blanketed over the oil and the mixture was agitated atambient temperature. After five hours, the lipase was removed from themixture and the jojoba derivative was analyzed. The transesterifiedproduct was a slightly yellow liquid similar in texture and color to theinitial feedstock. Measurement of the wax ester distributions for thefeedstock and both transesterified products was done using an HewlettPackard GC 5980 Series II gas chromatograph with a Restek MxT-65TG 30meter, 0.25 mm ID capillary chromatographic column with a Crossbond 65%diphenyl/35% dimethyl polysiloxane film thickness of 0.1 microns. Thegas chromatograph has split/splitless injection and uses an FIDdetector. Operating parameters of the gas chromatograph were as follows:injection port: 300 C, detector: 325 C, split ratio: 100:1, 1 microliterinjection with oven temperature ramping from 280° C. to 350° C. over 20minutes. Helium carrier gas was used. The concentration of tocopherolswas measured using HPLC rather than the gas chromatograph. The equipmentused was an Agilent LC 1100 series with an autosampler, quaternary pump,diode array detector (DAD), and an Alltech 2000 ELSD operating with adrift tube temperature of 40.0° C. with 1.7 mL/min Nitrogen. The columnused was an Agilent RX-SIL 4.6 × 50 mm 1.8 um normal phase silica columnkept at 40.0° C. The DAD was set to detect UV at wavelengths 210 nm and295 nm to identify the optically active portion of the tocopherols asthey eluted from the column. The mobile phase consisted of an isocraticflow of 98% hexane and 2% isopropanol at 0.5 mL/min with a total runtime of 15.00 minutes. Table 3 summarizes the results of bothexperiments.

TABLE 3 Components Feedstock Composition Chemical Catalyst % ChangeEnzyme Catalyst % Change Tocopherols 0.04% 0.00% -0.04% 0.04% 0.00%Fatty Acid Methyl Esters 0.00% 3.10% 3.10% 0.00% 0.00% Free FattyAlcohols 0.00% 1.80% 1.80% 0.00% 0.00% OSI (hours) 26.5 21.5 -18.87%38.6 45.66% Wax Ester Content 98.00% 93.10% -4.90% 98.00% 0.00% WaxEster Distribution C36:1 1.12% 1.30% 0.180% 1.20% 0.080% C38:2 6.02%4.90% -0.120% 4.80% -1.220% C40:2 27.95% 35.76% 7.810% 34.34% 6.390%C42:2 50.28% 40.64% -9.640% 40.92% -9.360% C44:2 9.94% 13.75% 3.811%14.93% 4.991% C46:2 1.20% 1.89% 0.690% 2.23% 1.030%

Examining the results shows that the formation of fatty acid methylesters and free fatty alcohols in the chemically catalyzedtransesterification reaction produces a product with a lower wax-esterpercentage than the original starting material. The results alsoindicate that the chemically catalyzed reaction destroys the originalamount of tocopherols present in the feedstock, which reduces the OSI ofthe transesterified product. Surprisingly, however, the OSI of theenzymatically catalyzed transesterified product is greater than that ofthe feedstock. This result indicates that the enzymatic catalysis has anunexpected positive effect on OSI that is not explainable simply by theenzymatic catalyst preserving the natural tocopherols originally presentin the feedstock during the reaction. The OSI was measured using anOmnion Scientific Services machine, Model OSI-8-110, according to theprocedures set forth in the American Oil Chemist’s Society (AOCS)Official Method Cd 12b-92, a copy of which is submitted herewith asAppendix A and incorporated entirely herein by reference.

In all of the above examples, no significant difference in the viscositybetween the chemically catalyzed and the enzymatically catalyzedtransesterified products was observed.

The chemically catalyzed and enzymatically catalyzed transesterifiedproducts were tested for performance in a typical cream formulation.Each cream formulation used 3% by weight of each transesterified product(chemically or enzymatically catalyzed) created in the previousexperiment. Table 4 shows the formulation details of the cream alongwith the components and suppliers. Following Table 4 is the mixingprocedure used.

TABLE 4 Phase Tradename International Nomenclature Cosmetic Ingredient(INCI) Supplier Weight percent % (of total) A Deionized Water Water -66.27 VERSENE™ Na2 Crystals Disodium EDTA The Dow Chemical Co. 0.03 BGlycerin, USP Glycerin The Dow Chemical Co. 5.00 KELTROL CG-T™ XanthanGum CP Kelco 0.30 C FLORAMAC™ Macadamia Oil. Macadamia integrifolia seedoil. Floratech 3.00 FLORAESTERS 30™ Jojoba Esters (and) TocopherolFloratech 3.00 Transesterified Wax Esters Jojoba Derivative beingexamined - 3.00 Cocoa Butter Theobroma cacao (Cocoa) seed butter CognisCorporation 5.00 FLORASUN 90™ Helianthus annuus (Sunflower) seed oil(and) Tocopherol Floratech 2.00 BOTANISIL CP-33™ CyclopentasiloxaneBotanigenics, Inc. 4.00 DOW CORNING 200™ Fluid Dimethicone Dow CorningCorporation 0.50 LEXEMUL 561™ Glyceryl Stearate (and) PEG-100 StearateInolex Chemicals 4.00 EMULGADE PL™ Cetearyl Glucoside (and) CetearylAlcohol Cognis Corporation 3.00 D PHENONIP™ Phenoxyethanol (and)Methylparaben (and) Ethylparaben (and) Butylparaben (and) Propylparaben(and) Isobutylparaben Clariant Corporation 0.90 Total 100

The cream was prepared as follows: Step 1: Dissolve the VERSENE™ Na2crystals into the deionized water with stirring at 75° C. to form phaseA. Step 2: Mix the KELTROL CG-T™ in the glycerin USP to form phase B.Add phase A to phase B with rapid stirring to form phase AB. Step 3:Combine all ingredients of phase C and 75° C. using propeller agitation.Add phase C to phase AB at 75° C. using propeller agitation to formphase ABC. Step 4: Reduce the temperature of the cream to 50° C. and addphase D to phase ABC with propeller agitation. Cool the batch withmoderate agitation to room temperature.

Table 5 summarizes the viscosity and appearance differences between thetwo cream formulations. While a viscometer can be used to measure theviscosity of such materials, the test used to calculate the viscosities,a method of calculating the viscosity without a viscometer, includesplacing a sample weighting 0.5 g on a piece of horizontally orientedpaper and drawing a starting line immediately next to the sample. Thepaper is then oriented vertically for 30 seconds and then laid flatagain. A line is then drawn at the edge of where the sample has finishedflowing down the paper. A ruler is then used to measure the distancebetween the starting line and the ending line. By developing acalibration curve for this method using materials of known viscosity andmeasuring the length of travel down the paper, a correlation can bedeveloped between the length of travel of the material and the viscosityof the material.

TABLE 5 Transesterified Product Type in Cream Viscosity AppearanceChemically Catalyzed 120,900 cP White, semi-solid phase EnzymaticallyCatalyzed 78,585 cP White, liquid phase, glossy

Table 5 indicates that the use of enzymatically catalyzedtransesterified jojoba oil created a cream formulation that had aviscosity drop of nearly 35% from the viscosity of the chemicallycatalyzed cream. This data indicates that the enzymatically catalyzedtransesterified jojoba oil has the functional effect of lowering theresulting product viscosity compared to chemically catalyzed product.The difference in appearance between the two cream formulations (i.e.,the enzymatically catalyzed product having less shine and gloss whenapplied to a surface) is due the relative abundance of fatty acid methylesters in the chemically catalyzed product.

Example 2. Continuous Flow Enzymatically Catalyzed TransesterificationUsing Lipase

A 10 cm × 100 cm stainless steel cylinder was filled with 0.5 kg ofLIPOZYME TL IM™ immobilized on substrates. The cylinder was equippedwith mesh screening material on both ends to secure the enzymesubstrates and was sealed and conditioned by evacuating the catalyst ofexcess moisture and salts used in the enzyme manufacturing process. Thecylinder was connected to a metering pump and a pressure gauge monitoredby a solenoid that automatically shut down flow if the pressure at theentrance to the cylinder rose above 15 psi. Flow rate was calculated bythe rate of conversion obtained from batch reactions using the sameenzymatic catalyst and was 0.8 kg/hr. A stock of refined jojoba oil wasfed to the reactor cylinder at a constant temperature and pressure, asthe cylinder was submerged in a water batch to keep the reactortemperature constant. The resulting product exiting the cylinder wasslightly yellow and liquid at room temperature. The properties of thetransesterified product produced are summarized in Table 6.

TABLE 6 Components Feedstock Composition Enzymatically Catalyzed %Change Tocopherols 0.04% 0.04% 0.00% Fatty Acid Methyl Esters 0.00%0.00% 0.00% Free Fatty Alcohols 0.00% 0.00% 0.00% OSI (hours) 26.5 36.236.6% Wax Ester Content 98% 98% 0% Wax Ester Distribution C36:1 1.121.20 0.080% C38:2 6.02 4.91 -1.110% C40:2 27.95 35.30 7.350% C42:2 50.2841.20 -9.080% C44:2 9.94 14.79 4.851% C46:2 1.2 2.14 0.940%

As can be observed, the continuous process created a fully randomizedtransesterified jojoba oil product that reached full conversion beforeexiting the reactor. Again, the increase in OSI from the feedstockmaterial was again surprisingly noted. The transesterified product inthis example was included in a cream formulation like that in Table 4and similar visual appearance and viscosity results to the enzymaticallycatalyzed cream in Table 5 were observed.

Example 3. Continuous Enzymatically Catalyzed Transesterification UsingJojoba Oil and Hydrogenated Jojoba Oil.

The same experimental system as in Example 2 was used but modified tooperate at 70 C in order to maintain a homogenous feedstock mixture ofjojoba oil and hydrogenated jojoba oil entering the reactor in thefeedstock. Various additional background information on the structure,use, and of transesterification reactions using hydrogenated jojoba waxesters may be found in the articles by James Brown and Robert Kleiman“Trans Isomers in Cosmetics”, Parts 1 and 2, Soap & Cosmetics, May 2001,p. 33-36 and June 2001, as well as in Sessa et al., “DifferentialScanning Calorimetry Index for Estimating Level of Saturation inTranseesterified Wax Esters,” J. Amer. Oil Chem. Soc., v. 73, 271-273(1996), and David J. Sessa, “Derivation of a Cocoa Butter Equivalentfrom Jojoba Transesterified Ester via a Differential ScanningCalorimetry Index,” J. Sci. Food Agric., v. 72, p. 295-298 (1996) thedisclosures of all of which are hereby entirely incorporated herein byreference.

Because of the absence of unsaturated wax esters in the hydrogenatedjojoba wax esters (HJW), the progress of the reaction can be measured byobserving the formation of monounsaturated wax esters during thereaction. The dropping point, or the temperature at which thetransesterified product transitions from a semi-solid to a liquid state,was also monitored. The dropping point was calculated using the methodoutlined in ASTM D127-63. The results of the processing, with acomparison to a feedstock containing no hydrogenated jojoba wax esters,are included in Table 7.

TABLE 7 Components Feedstock Composition 0% HJW 20% HJW 30% HJWTocopherols 0.04% 0.04% 0.04% 0.04% Fatty Acid Methyl Esters 0.00% 0.00%0.00% 0.00% Free Fatty Alcohols 0.00% 0.00% 0.00% 0.00% Wax EsterContent 98% 98% 98% 98% % Monounsaturated Wax Ester 3 3 31.98 41.50 %Conversion N/A 99.96% 100.55% 100.01% Dropping Point (degrees C) 8 8 4449

The percent conversion in Table 7 was calculated based on idealmonounsaturated wax ester values derived from the fatty acid and fattyalcohol proportions of the feedstock. These proportions (and the otherwax ester distribution data in this document) were determined using theHewlett Packard gas chromatograph disclosed herein and a solvent tosolubilize the samples. During testing, approximately 1 drop of samplewas diluted with 10 drops of solvent and 1.0 uL of the resulting mixturewas injected into the gas chromatograph. Based on historical data forjojoba wax esters previously obtained and a theoretical randomization ofthe percentage of the various chain lengths (assuming all esters weretransesterified), an ideal value for each wax ester species (i.e.,C36:2, C42:2, etc.) can be determined. Since the C42:2 ester is the onethat has the largest change from pre- to post-transesterification, it isthe one used in Example 3 to monitor conversion of the reactants. Theideal percentage of C42:2 in pure jojoba oil is 41.28% following acomplete and total randomization. Accordingly, the conversion of purejojoba oil can be calculated as:

% Conversion HJW0 = (% C42 : 2)/41.28 × 100

Where HJW0 is a jojoba oil feedstock that does not contain anyhydrogenated jojoba wax esters. For the feedstocks that includehydrogenated jojoba oil and wax esters, the percent conversion ismonitored by the formation of the monounsaturated species. The speciesmonitored in these reactions include C38:1, C40:1, C42:1, C44:1, andC46:1. The same gas chromatographic procedures used in this document areused to monitor the various reactants during and following thetransesterification reaction. Table 8 contains the ideal overall valuesfor monounsaturated wax esters (representing all the individual speciespercentages added together) for a feedstock containing 20%, 30%, and 50%hydrogenated jojoba wax esters (HJW20, HJW30, and HJW50, respectively).

TABLE 8 Product Ideal % of Monounsaturated Wax Esters HJW20 31.20 HJW3040.00 HJW50 46.50

These values can be used to calculate the percent conversion of jojobawax esters to the ideal mixture of monounsaturated wax esters given thepercentage of the monounsaturated components by weight in the feedstock.The calculation is given as follows:

% Conversion = (% Monounsaturates)/(Ideal % Monounsaturates) × 100

Because of the nature of the calculation it is possible for thecalculation to be greater than 100% depending upon measurement resultsand the fact that the ideal number is based on historical average datafor jojoba oil.

Referring to FIGS. 4-7 , various comparison graphs of wax esterdistributions for chemically catalyzed transesterified and enzymecatalyzed transesterified jojoba wax esters are illustrated. FIG. 4 isfor a pure jojoba oil product (HJW0). The solid line shows the wax esterdistribution for the chemically catalyzed process and the dotted lineshows the wax ester distribution for the enzymatically catalyzedprocess. By observation, it is clear that the enzymatically catalyzedprocess successfully randomizes the various esters very similarly to thechemically catalyzed process. FIGS. 5, 6, and 7 show the wax esterdistributions for transesterification products that have 20%, 30%, and50% by weight hydrogenated jojoba wax esters added in, respectively. Thesimilarity between the solid lines (chemical) and dotted (enzyme)demonstrate how the conversion rates of the enzymatic catalyzed processtrack those of the chemical catalyzed process. The differences betweenthe two processes may contribute in part to the differences infunctional performance and physical properties of the enzymaticallycatalyzed processed material from the chemically catalyzed material.

Lipases like those disclosed herein are conventionally used forprocessing triglycerides, and some have been specifically selected forprocessing triglycerides in particular ways. For example, some lipasesare known as 1, 3 specific as they are capable of scissioning the alkylesters in the 1 and 3 positions in a triglyceride while not affectingthe alkyl ester at the 2 position. Such a lipase interacts with thetriglyceride molecule on the exterior of the lipase surface. Otherlipases operate when the alkyl ester is inserted into the lipasemolecule itself. Obviously, 1, 3 lipases will differ in their ability toprocess various triglyceride molecules based on the structure of thealkyl esters and the triglyceride molecule due to various factors,including steric hindrance and other steric effects.

Interestingly, both 1, 3 lipases and lipases that operate usinginsertion of a triglyceride work equally well when used in jojoba estertransesterification reactions. This result is unexpected, as theselipases sterically interact quite differently with the molecules theyare involved in catalyzing. Without being bound by any theory, it ispossible that because a jojoba ester is primarily a long carbon chainwithout much molecular bending due to the ester group, both 1, 3 lipasesand lipases that operate using insertion are able to interact stericallywith the jojoba esters in ways that produce substantially the samecatalytic effect. In other words, the long chain jojoba ester can fitinto the opening in an insertion lipase and also slide into the activeareas of a 1, 3 lipase. As this processing characteristic for lipasecatalytic processing of jojoba wax esters is not a predictable result,this illustrates a unique aspect of processing jojoba wax esters usinglipases.

Furthermore, conventional processing of triglycerides using lipasestypically yields up to 4000 kg of product per kg of catalyst before thecatalyst must be replaced. A wide variety of factors are attributed tothe eventual denaturing of the catalyst, including gumming andcontamination of the catalyst with water in the triglyceride feedstock.An example of a conventional transesterification process of atriglyceride vegetable oil feedstock may be found in U.S. Pat.Application Publication No. 20130149414 to Favre et al., entitled“Processing of Vegetable Oils,” filed Jun. 28, 2011, and published Jun.13, 2013, the disclosure of which is incorporated entirely herein byreference. Testing using continuous flow reactors containing immobilizedlipases on substrates demonstrated 96 days of 100% conversion using 0.46kg of catalyst in each column. At the conclusion of this time period atwhich the catalyst needed to be replaced, 2305.15 kg of product wasproduced, which resulted in a kg of product to kg of catalyst ratio of5011. This ratio of kg of product to kg of immobilized catalyst is over20% greater than the ratio when the same lipase is used for triglycerideproduction. This result when the lipase is used for catalytictransesterification of jojoba oil significantly exceeds the conventionalexpectations for the lipase, and is an unexpected result that is notpredicted by the results of conventional enzymatic triglycerideprocessing. In various implementations, the yield of an enzymaticallytransesterified wax ester reaction may yield least 4001 kg product/kgimmobilized catalyst, at least 4100 kg product/kg immobilized catalyst,at least 4200 kg product/kg immobilized catalyst, at least 4300 kgproduct/kg immobilized catalyst, at least 4500 kg product/kg immobilizedcatalyst, at least 4700 kg product/kg immobilized catalyst, at least48000 kg product/kg of immobilized catalyst, at least 4900 kg product/kgof immobilized catalyst, or even at least 5000 kg product/kg ofimmobilized catalyst.

In places where the description above refers to particularimplementations of enzymatic catalytic transesterification systems,processes, and implementing components, sub-components, methods andsub-methods, it should be readily apparent that a number ofmodifications may be made without departing from the spirit thereof andthat these implementations, implementing components, sub-components,methods and sub-methods may be applied to other enzymatic catalytictransesterification systems and processes.

What is claimed is:
 1. A process for preparing wax esters, the processcomprising: reacting a feedstock with a lipase to yield a productwherein; the feedstock comprises jojoba wax esters and the jojoba waxesters comprise less than 50% by weight hydrogenated jojoba wax estersand wherein the oxidative stability index of the product is greater than26.5 hours as measured by the American Oil Chemist’s Society OfficialMethod Cd 12b-92.
 2. The process of claim 1, wherein the jojoba waxesters comprise 20%-50% hydrogenated jojoba wax esters.
 3. The processof claim 2, wherein the jojoba wax esters comprise 20% hydrogenatedjojoba wax esters.
 4. The process of claim 2, wherein the feedstockconsists essentially of jojoba wax esters.
 5. The process of claim 4,wherein the feedstock further comprises an antioxidant.
 6. The processof claim 5, wherein the antioxidant comprises one or more tocopherols.7. The process of claim 3, wherein the feedstock consists essentially ofjojoba wax esters.
 8. The process of claim 7, wherein the feedstockfurther comprises an antioxidant.
 9. The process of claim 8, wherein theantioxidant comprises one or more tocopherols.
 10. The process of claim1, wherein the product comprises less than 3.1% fatty acid methylesters.
 11. The process of claim 1, wherein the feedstock furthercomprises an antioxidant.
 12. The process of claim 11, wherein theantioxidant comprises one or more tocopherols.
 13. The process of claim1, wherein the feedstock does not contain a free fatty acid alcohol. 14.The process of claim 1, wherein the product does not contain a freefatty acid alcohol.
 15. The process of claim 13, wherein the productdoes not contain a free fatty acid alcohol.
 16. The process of claim 2,wherein the feedstock does not contain a free fatty acid alcohol. 17.The process of claim 2, wherein the product does not contain a freefatty acid alcohol.
 18. The process of claim 16, wherein the productdoes not contain a free fatty acid alcohol.
 19. The process of claim 2,wherein the product comprises less than 3.1% fatty acid methyl esters.20. The process of claim 18, wherein the product comprises less than3.1% fatty acid methyl esters.
 21. The process of claim 1, wherein thelipase is a 1,3 selective lipase or a lipase that operates usinginsertion.
 22. The process of claim 2, wherein the lipase is a 1,3selective lipase or a lipase that operates using insertion.
 23. Theprocess of claim 20, wherein the lipase is a 1,3 selective lipase or alipase that operates using insertion.
 24. The process of claim 1,wherein the process comprises continuously reacting the feedstock withthe lipase.
 25. The process of claim 2, wherein the process comprisescontinuously reacting the feedstock with the lipase.
 26. The process ofclaim 20, wherein the process comprises continuously reacting thefeedstock with the lipase.